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July 12, 1932.

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M. MALLORY GOVERNOR BRAKE FOR TIMERS Filed March 7, 1930 gwuenkw Patented July 12, 1932 mron mLLoaY, or TOLEDO, x10

GOVERNOR BRAKE FOR TIMEBB Application tiled March 7,

This invention relates to ignition timers and especially to a brake ada ted to be associated with a governor whici controls the advance or retardation of the spark in ac- 3 cordance with certain conditions. In timers which are provided with an automatic governor, the cam which operates the circuit breaker is ordinarily carried by a sleeve which is circumferentially adjustable with relation to the timer shaft in response to variations in the centrifugal force exerted by the governor. As the cam engages the circuit breaker, the inertia or friction of the latter opposes the action of the governor and causes a back lash which tends to cause a very noisy operation of the timer. 7

With the above conditions in mind, an important object of my invention is to provide a brake or drag to act on the sleeve which carries the circuit breaker so as to prevent back lash and insure a practically noiseless operation. The action of the brake has another advantage in that it delays the advance of the spark in response to a quick opening of the throttle, until the motor picks up speed with a corresponding increase inthe force exerted by the governor.

The brake may be mounted in various ways, but inasmuch as both the timer shaft and the sleeve normally rotatecontinuously, it is preferred to mount the brake so that it is carried by one of these rotating members and exerts continuous pressure against the other. Thus there is no wear on the brake and no power is consumed by the friction of the brake as long as the timer shaft and sleeve are rotating at constant speed.

The preferred form of the invention will be explained more in detail in connection with the accompanying drawing, in which Figure 1 is a side elevation of the upper end of a timer shaft with the cam which operates the circuit breaker mounted thereon.

Figure 2 is a vertical sectional view of the same,

Figure 3 is a section taken on the line 33 of Figure 2.

Figure 4 is a section taken on the line 44 of Figure 1.

As shown in the drawing, the invention is mo. Serial No. 434,181.

associated with a timer shaft 5 at the upper end of which isa sleeve 6. The usual cam 7 is secured to the sleeve 6 for actuating the circuit breaker and the sleeve is formed with a non-circular upper end 8 on which the distributor head is adapted to be mounted.

The sleeve 6 is adapted to have a limited circumferential movement with relation to the shaft 5, which movement is automatically controlled by a governor in accordance with certain conditions. This control is effected through the medium of a plate 9 secured to the sleeve. As a convenient means for securing plate 9, the sleeve is formed with a circumferential flange 10 against which the plate 9 is secured by a clamping plate 11 and screws 12. The plate 9 is formed with a slot 13 associated with which is a centrifugal governor indicated in dotted lines at 14 in Figure 3. The slot 13 may-be so shaped as to control the advance of the spark in the manner desired. Since the governor itself constitutes no part of the present invention, a further description thereof is unnecessary. A complete description of the governor may, however, be found in my co-pending application Ser. No. 408,612.

In accordance with the present invention, in order to prevent back lash as the cam 7 engages the circuit breaker, a brake is provided which is preferably carried by one of the rotating members 5, 6, andacts on the other tending to prevent relative movement of these members. As long as the two members 5 and 6 rotate together at constant speed the brake offers no resistance. In the present adaptation of this brake, the sleeve 6 is formed with a hole 15 extending through one side thereof to receive a brake element 16 which is adapted to bear against the shaft 5 by rea son of a resilient split ring 17 which is secured to the element 16 and engages a circumferential groove 18 which is formed in the sleeve 6 and connects with the hole 15.

The upper end of the sleeve 6 extends above the end of the shaft 5 and the latter has a recess 19 formed in its upper end to receive lubricant. As the timer rotates, therefore,

' this lubricant will work between the shaft 5 and the sleeve 6.

(P. in;

While I have shown and described in detail the preferred form of the invention, it is apparent that the same may be considerably modified within the scope of the appended claims without departing materially rom the scope of the invention.

What I claim is:

1. An ignition timer comprising a rotatable shaft, a cam normally rotatable with the shaft but capable of a limited relative circumferential movement with respect thereto, a governor for controlling said relative circumferential movement, and a brake held for rotation with one of said rotatable members and engaging the other to resist said relative circumferential movement.

2. An ignition timer comprising a rotatable shaft, a cam normally rotatable with the shaft but capable of a limited relative circumferential movement with respect thereto, a governor for controlling said relative circumferential movement, a friction member keyed to one of said rotatable members and resilient means causing said friction member to engage the other rotatable member.

3. An ignition timer comprising a rotatable shaft, a sleeve normally rotatable with the shaft but capable of a limited circumferential movement with relation thereto, a cam secured to the sleeve, a governor for controlling the relative movement of the sleeve, said sleeve having a hole through one side, a brake elementmounted in said'hole, and resilient means acting on said brake element to cause it to frictionally engage the shaft.

4. An ignition timer comprising a rotatable shaft, a sleeve normally rotatable with the shaft but capable of a limited circumferential movement with relation thereto, a cam secured to the sleeve, a governor for controlling the relative movement of the sleeve, said sleeve having a hole through one side, and a circumferential groove connecting with said hole, a brake element mounted in said hole, and a resilient ring in said groove and connected with the brake element, causing the latter to frictionally engage the shaft.

5. An ignition timer comprising a timer shaft, a sleeve carried thereby and extending above the upper end thereof, a cam secured to the sleeve, said sleeve having a limited relative circumferential movement with respect to the shaft, and a brake resisting relative movement between the shaft and sleeve.

6. An ignition timer comprising a timer shaft, a sleeve carried thereby and extending above the upper end thereof, a cam secured to the sleeve, said sleeve having a limited relative circumferential movement with respect to the shaft, and a brake actin between the shaft and sleeve, said shaft ing formed with a recess in its upper end for receiving lubricant.

7. An ignition timer comprising a timer shaft, a sleeve carried by said shaft and having a limited relative circumferential movement with respect thereto, a cam movable circumferentially with said sleeve, a governor for controlling the circumferential movement of the sleeve and cam, and a brake resis'ting said relative circumferential movement.

8. An ignition timer comprising a timer shaft, a sleeve carried by said shaft and hav- 

